More than 60 percent of people worldwide spend more than three hours a day sitting down, and the researchers calculated that sitting time contributed to some 433,000 deaths a year from 2002 through 2011.

They estimated mean sitting time across countries at 4.7 hours a day. Reducing that time by 50 percent, they calculated, would result in a 2.3 percent decline in all-cause mortality.

The association between time spent sitting and mortality has been found in other studies, and the link persists even after accounting for other physical exercise.

“This is the best data we have for now,” said the lead author, Leandro Rezende, a doctoral candidate at the University of São Paulo School of Medicine, “but we don’t know if it’s a causal relationship.

“There are things we can do,” he continued. “Stand up, and go have a drink of water instead of keeping the water bottle at your desk. Or just stand up every so often. Standing alone increases your energy expenditure.”

A version of this article appears in print on 04/05/2016, on page D4 of the NewYork edition with the headline: Exercise; Stand Up to Live Longer.